Hot oil pump preheating issue

The pump must maintain stable operation during both preheating and switching processes. It’s better to go slower rather than affect other operations. When starting up, it can be opened slightly to allow for gradual warming up. A pre-heating element is used to raise the temperature after it is filled. The shaft needs to be rotated frequently to ensure even heating.

This pump is really problematic; all the other hot oil pumps work fine, but this one doesn’t – it gets emptied every time. The manager doesn’t have a good solution either; they only changed the way of filling the pump, but the results weren’t very satisfactory. Do you have any good methods for filling the pump?

A preheating pump is essential; generally, the slurry pump should be preheated as well. It involves a very small pipeline, and if the inlet size is too large, it will affect the flow rate of the pump. A smaller size is sufficient for proper preheating. However, it’s necessary to check the oil regularly; once it cools down, start the pump to circulate the cool oil.

If that’s the case, you can try filling the pump directly with preheated liquid; open the inlet slightly once it’s almost full. Regular turning of the shaft is necessary.

Thank you for the reply. All these factors have been taken into consideration. It’s just that this pump is quite special and difficult to handle. There’s nothing wrong with the preheating method; it’s just that when filling the pump, do you have any other ways of doing it, such as filling it through the preheating line, or by first filling it with oil?

Well, I have used this method before, but it still causes the pump to run out of pressure; it’s difficult to operate, and there have been cases where it was started too quickly or with too high a intensity

Is there a light component, or is there a leak in the steam valve used for cleaning?

Judging from your question, I guess the pump has been repaired and checked to be in good condition. 1: Fill the pump with sealing oil to test the static pressure ； 2: Slightly open pump inlet ； 3: Pre-heating line outlet ； 4: The opening of the pre-heating line outlet results in the pump being evacuated. I wonder if it is?

Never mind, I’ll just tell you the reason directly. 1: If the pump is not first filled with oil to test the static pressure, then fill it with oil first to test the static pressure ； 2: If static pressure testing was performed on the filling pump, it is possible that the sealing oil contains water or that its components are too light. 3: If it’s not one of the above two reasons, then it’s because you’re being lazy and didn’t try using static pressure or removing air before opening the inlet valve. Correct steps: 1. Feed seal oil into the pump chamber through the pump’s end face; allow seal oil to flow for 1–5 minutes at the outlet, then close the outlet drain valve. 2. Monitor the pressure gauge at the pump outlet until the maximum seal oil pressure is reached, then close the seal oil valve ； 3: Check if the pump is leaking; there is no leakage ； 4: Open the inlet valve of the pump; observe the outlet pressure of the preheating pump gradually decreasing, and then open the outlet valve of the preheating line. If there is still time, it’s possible that the oil will be sealed along with water (high probability), or the oil-sealing component might be too light (low probability; solutions can be discussed if that happens). Give it a try and see if you have time?

First, fill the pump with seal oil, and use the oil return line to remove any water present in the system, so that the temperature of the standby pump reaches that of the seal oil. Then, slowly open the inlet valve and raise the temperature gradually through a pre-heating line, in order to prevent damage to the seals. It’s very simple: what do your managers do? The bottom circulation in coking plants works in this way, and cleaning is required frequently.